This invention relates in general to body and frame assemblies for vehicles. More specifically, this invention relates to an improved structure for a closed channel structural member, such as a side rail or a cross member, for use in such a vehicle body and frame assembly that includes an internal reinforcing structure to increase the strength and rigidity thereof.
Many land vehicles in common use, such as automobiles, vans, and trucks, include a body and frame assembly that is supported upon a plurality of groundengaging wheels by a resilient suspension system. The structures of known body and frame assemblies can be divided into two general categories, namely, separate and unitized. In a typical separate body and frame assembly, the structural components of the body portion and the frame portion of the vehicle are separate and independent from one another. When assembled, the frame portion of the assembly is resiliently supported upon the vehicle wheels by the suspension system and serves as a platform upon which the body portion of the assembly and other components of the vehicle can be mounted. Separate body and frame assemblies of this general type are found in most older vehicles, but remain in common use today for many relatively large or specialized use modern vehicles, such as large vans, sport utility vehicles, and trucks. In a typical unitized body and frame assembly, the structural components of the body portion and the frame portion are combined into an integral unit that is resiliently supported upon the vehicle wheels by the suspension system. Unitized body and frame assemblies of this general type are found in many relatively small modern vehicles, such as automobiles and minivans.
Traditionally, the various components of vehicular body and frame assemblies have been formed from open channel structural members, i.e., structural members that have a non-continuous cross sectional shape (such as U-shaped or C-shaped channel members, for example). For example, it is known to use one or more open channel structural members to form the side rails, the cross members, and other components of a ladder frame type of separate body and frame assembly. However, the use of open channel structural members to form the various components of vehicular body and frame assemblies has been found to be undesirable for several reasons. To address this, it has been proposed to form one or more of the components of the vehicular body and frame assemblies from closed channel structural members, i.e., structural members that have a continuous cross sectional shape (such as tubular or box-shaped channel members, for example). This cross sectional shape is advantageous because it provides strength and rigidity to the vehicle body and frame component. Also, closed channel structural member are well suited to be deformed to a desired shape by hydroforming, which is a well known process that uses pressurized fluid supplied within the closed channel structural member to deform it into conformance with a surrounding die. Hydroforming has been found to be a desirable forming process because portions of a closed channel structural member can be quickly and easily deformed to have a complex cross sectional shape.
Although closed channel structural members provide strength and rigidity to the vehicle body and frame component, there are instances where it is necessary or desirable to further increase the strength and rigidity thereof. For example, it may be necessary or desirable to reinforce the strength of a closed channel structural member at one or more locations throughout the length thereof to prevent deformation under extreme operating conditions, such as during a collision. Also, it may be desirable to reinforce the strength of a closed: channel structural member at one or more locations throughout the length thereof where mounting brackets or other ancillary components are secured thereto. Because of their inherent closed cross sectional shapes, however, it has been found to be difficult to provide such reinforcement in closed channel structural members, particularly without changing the shape of outer surface thereof. Thus, it would be desirable to provide an improved structure for a closed channel structural member, such as a side rail or a cross member, for use in a vehicle body and frame assembly, that includes an internal reinforcing structure to increase the strength and rigidity thereof.
This invention relates to an improved structure for a closed channel structural member, such as a side rail or a cross member, for use in such a vehicle body and frame assembly that includes an internal reinforcing structure to increase the strength and rigidity thereof. The side rail can be generally rectangular in cross sectional shape, including first and second side rail sections having generally C-shaped cross sectional shapes. The reinforcing structure can be generally hat-shaped or W-shaped in cross sectional shape, including a central reinforcing portion extending between a pair of base portions. The central reinforcing portion can either be laterally spaced apart from or directly abut a central web portion of one of the side rail sections. The base portions can be generally L-shaped in cross sectional shape, including legs that terminate adjacent to the ends of the other of the side rail sections to facilitate the assembly process. A pair of such,reinforcing structures can be disposed within the side rail and abut one another in end-to-end fashion. Alternatively, tabs extending from each of the reinforcing structures can partially overlap one another to provide additional strength and rigidity.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.